Safety warning lamps for adverse or hazardous atmospheres

Abstract

A warning lamp for use in hazardous atmospheres including three air-filled volumes interconnected by a passageway between screw threads whereby, in the event of an explosion, each of the volumes stores a quantity of explosive gases prior to permitting escape thereof along the passageway between the screw threads thereby providing a warning lamp which causes hot gases to be cooled sufficiently and quenched in the three volumes therein.

I claim: 
     
       1. A warning lamp for use in hazardous atmospheres comprising a hollow base member having an open end,   a plate member connected to the base member across the open end thereof, said plate member having a centrally-disposed aperture therethrough, being circular, and having peripheral surfaces with a first screw threaded portion and a second screw threaded portion,   a hollow housing having an open end and having a screw threaded portion adjacent its open end engaging said first screw threaded portion of said plate member within the hollow base member and defining a first air filled volume between the housing and the base member,   a plug for receiving a light-emitting, said plug being mounted within said hollow housing and projecting into the aperture in the plate member,   a light-emitting element in the form of a xenon gas-discharge lamp secured to said plug and projecting to the other side of the plate member from said hollow housing,   a transparent light-magnification dome mounted on said plate member and surrounding said gas-discharge lamp to define a second air filled volume between the lamp and the dome,   a generally cylindrical transparent protective dome formed of polycarbonate and surrounding the light focusing dome to define a third air filled volume between the magnification dome and the protective dome,   electrical control means encapsulated in a potting compound within said hollow housing and connected to said plug to cause said light-emitting element to flash intermittently, said protective dome having a screw threaded portion on its outer surface adjacent its open end, and the hollow base member being cylindrical and having a screw-threaded portion on its inner surface adjacent its opening end engaging the screw-threads of the second screw threaded portion on said peripheral surface of the circular plate member and the screw-threads on said protective dome, said screw-threads forming a passageway for escaping hot gases wherein a temperature reduction occurs, whereby in the event of an explosion each of said volumes stores a quantity of explosive gases prior to permitting escape thereof along said passageway.   
     
     
       2. The warning lamp of claim 1, wherein said gas-discharge lamp includes a control electrode, an anode and a cathode and wherein said electrical control means comprises a pair of input terminals for receiving an AC voltage supply, an oscillator circuit connected to said input terminals, a silicon controlled rectifier having anode and cathode electrodes connected to said input terminals and having a trigger electrode connected to the output of said oscillator circuit, and first and second mutually-coupled inductance coils, the first of said coils being connected in parallel with said silicon controlled rectifier and the second of said coils being connected to the control electrode of the gas-discharge lamp, the anode and cathode of said gas-discharge lamp being connected to said input terminals.